Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 1585 insertions, 0 deletions

diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
new file mode 100644
index 00000000000..05907035bc9
--- /dev/null
+++ b/net/sunrpc/svcsock.c
@@ -0,0 +1,1585 @@
+/*
+ * linux/net/sunrpc/svcsock.c
+ *
+ * These are the RPC server socket internals.
+ *
+ * The server scheduling algorithm does not always distribute the load
+ * evenly when servicing a single client. May need to modify the
+ * svc_sock_enqueue procedure...
+ *
+ * TCP support is largely untested and may be a little slow. The problem
+ * is that we currently do two separate recvfrom's, one for the 4-byte
+ * record length, and the second for the actual record. This could possibly
+ * be improved by always reading a minimum size of around 100 bytes and
+ * tucking any superfluous bytes away in a temporary store. Still, that
+ * leaves write requests out in the rain. An alternative may be to peek at
+ * the first skb in the queue, and if it matches the next TCP sequence
+ * number, to extract the record marker. Yuck.
+ *
+ * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
+ */
+
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/net.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/udp.h>
+#include <linux/tcp.h>
+#include <linux/unistd.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <net/checksum.h>
+#include <net/ip.h>
+#include <net/tcp.h>
+#include <asm/uaccess.h>
+#include <asm/ioctls.h>
+
+#include <linux/sunrpc/types.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/svcsock.h>
+#include <linux/sunrpc/stats.h>
+
+/* SMP locking strategy:
+ *
+ * 	svc_serv->sv_lock protects most stuff for that service.
+ *
+ *	Some flags can be set to certain values at any time
+ *	providing that certain rules are followed:
+ *
+ *	SK_BUSY  can be set to 0 at any time.  
+ *		svc_sock_enqueue must be called afterwards
+ *	SK_CONN, SK_DATA, can be set or cleared at any time.
+ *		after a set, svc_sock_enqueue must be called.	
+ *		after a clear, the socket must be read/accepted
+ *		 if this succeeds, it must be set again.
+ *	SK_CLOSE can set at any time. It is never cleared.
+ *
+ */
+
+#define RPCDBG_FACILITY	RPCDBG_SVCSOCK
+
+
+static struct svc_sock *svc_setup_socket(struct svc_serv *, struct socket *,
+					 int *errp, int pmap_reg);
+static void		svc_udp_data_ready(struct sock *, int);
+static int		svc_udp_recvfrom(struct svc_rqst *);
+static int		svc_udp_sendto(struct svc_rqst *);
+
+static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk);
+static int svc_deferred_recv(struct svc_rqst *rqstp);
+static struct cache_deferred_req *svc_defer(struct cache_req *req);
+
+/*
+ * Queue up an idle server thread.  Must have serv->sv_lock held.
+ * Note: this is really a stack rather than a queue, so that we only
+ * use as many different threads as we need, and the rest don't polute
+ * the cache.
+ */
+static inline void
+svc_serv_enqueue(struct svc_serv *serv, struct svc_rqst *rqstp)
+{
+	list_add(&rqstp->rq_list, &serv->sv_threads);
+}
+
+/*
+ * Dequeue an nfsd thread.  Must have serv->sv_lock held.
+ */
+static inline void
+svc_serv_dequeue(struct svc_serv *serv, struct svc_rqst *rqstp)
+{
+	list_del(&rqstp->rq_list);
+}
+
+/*
+ * Release an skbuff after use
+ */
+static inline void
+svc_release_skb(struct svc_rqst *rqstp)
+{
+	struct sk_buff *skb = rqstp->rq_skbuff;
+	struct svc_deferred_req *dr = rqstp->rq_deferred;
+
+	if (skb) {
+		rqstp->rq_skbuff = NULL;
+
+		dprintk("svc: service %p, releasing skb %p\n", rqstp, skb);
+		skb_free_datagram(rqstp->rq_sock->sk_sk, skb);
+	}
+	if (dr) {
+		rqstp->rq_deferred = NULL;
+		kfree(dr);
+	}
+}
+
+/*
+ * Any space to write?
+ */
+static inline unsigned long
+svc_sock_wspace(struct svc_sock *svsk)
+{
+	int wspace;
+
+	if (svsk->sk_sock->type == SOCK_STREAM)
+		wspace = sk_stream_wspace(svsk->sk_sk);
+	else
+		wspace = sock_wspace(svsk->sk_sk);
+
+	return wspace;
+}
+
+/*
+ * Queue up a socket with data pending. If there are idle nfsd
+ * processes, wake 'em up.
+ *
+ */
+static void
+svc_sock_enqueue(struct svc_sock *svsk)
+{
+	struct svc_serv	*serv = svsk->sk_server;
+	struct svc_rqst	*rqstp;
+
+	if (!(svsk->sk_flags &
+	      ( (1<<SK_CONN)|(1<<SK_DATA)|(1<<SK_CLOSE)|(1<<SK_DEFERRED)) ))
+		return;
+	if (test_bit(SK_DEAD, &svsk->sk_flags))
+		return;
+
+	spin_lock_bh(&serv->sv_lock);
+
+	if (!list_empty(&serv->sv_threads) && 
+	    !list_empty(&serv->sv_sockets))
+		printk(KERN_ERR
+			"svc_sock_enqueue: threads and sockets both waiting??\n");
+
+	if (test_bit(SK_DEAD, &svsk->sk_flags)) {
+		/* Don't enqueue dead sockets */
+		dprintk("svc: socket %p is dead, not enqueued\n", svsk->sk_sk);
+		goto out_unlock;
+	}
+
+	if (test_bit(SK_BUSY, &svsk->sk_flags)) {
+		/* Don't enqueue socket while daemon is receiving */
+		dprintk("svc: socket %p busy, not enqueued\n", svsk->sk_sk);
+		goto out_unlock;
+	}
+
+	set_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
+	if (((svsk->sk_reserved + serv->sv_bufsz)*2
+	     > svc_sock_wspace(svsk))
+	    && !test_bit(SK_CLOSE, &svsk->sk_flags)
+	    && !test_bit(SK_CONN, &svsk->sk_flags)) {
+		/* Don't enqueue while not enough space for reply */
+		dprintk("svc: socket %p  no space, %d*2 > %ld, not enqueued\n",
+			svsk->sk_sk, svsk->sk_reserved+serv->sv_bufsz,
+			svc_sock_wspace(svsk));
+		goto out_unlock;
+	}
+	clear_bit(SOCK_NOSPACE, &svsk->sk_sock->flags);
+
+	/* Mark socket as busy. It will remain in this state until the
+	 * server has processed all pending data and put the socket back
+	 * on the idle list.
+	 */
+	set_bit(SK_BUSY, &svsk->sk_flags);
+
+	if (!list_empty(&serv->sv_threads)) {
+		rqstp = list_entry(serv->sv_threads.next,
+				   struct svc_rqst,
+				   rq_list);
+		dprintk("svc: socket %p served by daemon %p\n",
+			svsk->sk_sk, rqstp);
+		svc_serv_dequeue(serv, rqstp);
+		if (rqstp->rq_sock)
+			printk(KERN_ERR 
+				"svc_sock_enqueue: server %p, rq_sock=%p!\n",
+				rqstp, rqstp->rq_sock);
+		rqstp->rq_sock = svsk;
+		svsk->sk_inuse++;
+		rqstp->rq_reserved = serv->sv_bufsz;
+		svsk->sk_reserved += rqstp->rq_reserved;
+		wake_up(&rqstp->rq_wait);
+	} else {
+		dprintk("svc: socket %p put into queue\n", svsk->sk_sk);
+		list_add_tail(&svsk->sk_ready, &serv->sv_sockets);
+	}
+
+out_unlock:
+	spin_unlock_bh(&serv->sv_lock);
+}
+
+/*
+ * Dequeue the first socket.  Must be called with the serv->sv_lock held.
+ */
+static inline struct svc_sock *
+svc_sock_dequeue(struct svc_serv *serv)
+{
+	struct svc_sock	*svsk;
+
+	if (list_empty(&serv->sv_sockets))
+		return NULL;
+
+	svsk = list_entry(serv->sv_sockets.next,
+			  struct svc_sock, sk_ready);
+	list_del_init(&svsk->sk_ready);
+
+	dprintk("svc: socket %p dequeued, inuse=%d\n",
+		svsk->sk_sk, svsk->sk_inuse);
+
+	return svsk;
+}
+
+/*
+ * Having read something from a socket, check whether it
+ * needs to be re-enqueued.
+ * Note: SK_DATA only gets cleared when a read-attempt finds
+ * no (or insufficient) data.
+ */
+static inline void
+svc_sock_received(struct svc_sock *svsk)
+{
+	clear_bit(SK_BUSY, &svsk->sk_flags);
+	svc_sock_enqueue(svsk);
+}
+
+
+/**
+ * svc_reserve - change the space reserved for the reply to a request.
+ * @rqstp:  The request in question
+ * @space: new max space to reserve
+ *
+ * Each request reserves some space on the output queue of the socket
+ * to make sure the reply fits.  This function reduces that reserved
+ * space to be the amount of space used already, plus @space.
+ *
+ */
+void svc_reserve(struct svc_rqst *rqstp, int space)
+{
+	space += rqstp->rq_res.head[0].iov_len;
+
+	if (space < rqstp->rq_reserved) {
+		struct svc_sock *svsk = rqstp->rq_sock;
+		spin_lock_bh(&svsk->sk_server->sv_lock);
+		svsk->sk_reserved -= (rqstp->rq_reserved - space);
+		rqstp->rq_reserved = space;
+		spin_unlock_bh(&svsk->sk_server->sv_lock);
+
+		svc_sock_enqueue(svsk);
+	}
+}
+
+/*
+ * Release a socket after use.
+ */
+static inline void
+svc_sock_put(struct svc_sock *svsk)
+{
+	struct svc_serv *serv = svsk->sk_server;
+
+	spin_lock_bh(&serv->sv_lock);
+	if (!--(svsk->sk_inuse) && test_bit(SK_DEAD, &svsk->sk_flags)) {
+		spin_unlock_bh(&serv->sv_lock);
+		dprintk("svc: releasing dead socket\n");
+		sock_release(svsk->sk_sock);
+		kfree(svsk);
+	}
+	else
+		spin_unlock_bh(&serv->sv_lock);
+}
+
+static void
+svc_sock_release(struct svc_rqst *rqstp)
+{
+	struct svc_sock	*svsk = rqstp->rq_sock;
+
+	svc_release_skb(rqstp);
+
+	svc_free_allpages(rqstp);
+	rqstp->rq_res.page_len = 0;
+	rqstp->rq_res.page_base = 0;
+
+
+	/* Reset response buffer and release
+	 * the reservation.
+	 * But first, check that enough space was reserved
+	 * for the reply, otherwise we have a bug!
+	 */
+	if ((rqstp->rq_res.len) >  rqstp->rq_reserved)
+		printk(KERN_ERR "RPC request reserved %d but used %d\n",
+		       rqstp->rq_reserved,
+		       rqstp->rq_res.len);
+
+	rqstp->rq_res.head[0].iov_len = 0;
+	svc_reserve(rqstp, 0);
+	rqstp->rq_sock = NULL;
+
+	svc_sock_put(svsk);
+}
+
+/*
+ * External function to wake up a server waiting for data
+ */
+void
+svc_wake_up(struct svc_serv *serv)
+{
+	struct svc_rqst	*rqstp;
+
+	spin_lock_bh(&serv->sv_lock);
+	if (!list_empty(&serv->sv_threads)) {
+		rqstp = list_entry(serv->sv_threads.next,
+				   struct svc_rqst,
+				   rq_list);
+		dprintk("svc: daemon %p woken up.\n", rqstp);
+		/*
+		svc_serv_dequeue(serv, rqstp);
+		rqstp->rq_sock = NULL;
+		 */
+		wake_up(&rqstp->rq_wait);
+	}
+	spin_unlock_bh(&serv->sv_lock);
+}
+
+/*
+ * Generic sendto routine
+ */
+static int
+svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
+{
+	struct svc_sock	*svsk = rqstp->rq_sock;
+	struct socket	*sock = svsk->sk_sock;
+	int		slen;
+	char 		buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
+	struct cmsghdr *cmh = (struct cmsghdr *)buffer;
+	struct in_pktinfo *pki = (struct in_pktinfo *)CMSG_DATA(cmh);
+	int		len = 0;
+	int		result;
+	int		size;
+	struct page	**ppage = xdr->pages;
+	size_t		base = xdr->page_base;
+	unsigned int	pglen = xdr->page_len;
+	unsigned int	flags = MSG_MORE;
+
+	slen = xdr->len;
+
+	if (rqstp->rq_prot == IPPROTO_UDP) {
+		/* set the source and destination */
+		struct msghdr	msg;
+		msg.msg_name    = &rqstp->rq_addr;
+		msg.msg_namelen = sizeof(rqstp->rq_addr);
+		msg.msg_iov     = NULL;
+		msg.msg_iovlen  = 0;
+		msg.msg_flags	= MSG_MORE;
+
+		msg.msg_control = cmh;
+		msg.msg_controllen = sizeof(buffer);
+		cmh->cmsg_len = CMSG_LEN(sizeof(*pki));
+		cmh->cmsg_level = SOL_IP;
+		cmh->cmsg_type = IP_PKTINFO;
+		pki->ipi_ifindex = 0;
+		pki->ipi_spec_dst.s_addr = rqstp->rq_daddr;
+
+		if (sock_sendmsg(sock, &msg, 0) < 0)
+			goto out;
+	}
+
+	/* send head */
+	if (slen == xdr->head[0].iov_len)
+		flags = 0;
+	len = sock->ops->sendpage(sock, rqstp->rq_respages[0], 0, xdr->head[0].iov_len, flags);
+	if (len != xdr->head[0].iov_len)
+		goto out;
+	slen -= xdr->head[0].iov_len;
+	if (slen == 0)
+		goto out;
+
+	/* send page data */
+	size = PAGE_SIZE - base < pglen ? PAGE_SIZE - base : pglen;
+	while (pglen > 0) {
+		if (slen == size)
+			flags = 0;
+		result = sock->ops->sendpage(sock, *ppage, base, size, flags);
+		if (result > 0)
+			len += result;
+		if (result != size)
+			goto out;
+		slen -= size;
+		pglen -= size;
+		size = PAGE_SIZE < pglen ? PAGE_SIZE : pglen;
+		base = 0;
+		ppage++;
+	}
+	/* send tail */
+	if (xdr->tail[0].iov_len) {
+		result = sock->ops->sendpage(sock, rqstp->rq_respages[rqstp->rq_restailpage], 
+					     ((unsigned long)xdr->tail[0].iov_base)& (PAGE_SIZE-1),
+					     xdr->tail[0].iov_len, 0);
+
+		if (result > 0)
+			len += result;
+	}
+out:
+	dprintk("svc: socket %p sendto([%p %Zu... ], %d) = %d (addr %x)\n",
+			rqstp->rq_sock, xdr->head[0].iov_base, xdr->head[0].iov_len, xdr->len, len,
+		rqstp->rq_addr.sin_addr.s_addr);
+
+	return len;
+}
+
+/*
+ * Check input queue length
+ */
+static int
+svc_recv_available(struct svc_sock *svsk)
+{
+	mm_segment_t	oldfs;
+	struct socket	*sock = svsk->sk_sock;
+	int		avail, err;
+
+	oldfs = get_fs(); set_fs(KERNEL_DS);
+	err = sock->ops->ioctl(sock, TIOCINQ, (unsigned long) &avail);
+	set_fs(oldfs);
+
+	return (err >= 0)? avail : err;
+}
+
+/*
+ * Generic recvfrom routine.
+ */
+static int
+svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr, int buflen)
+{
+	struct msghdr	msg;
+	struct socket	*sock;
+	int		len, alen;
+
+	rqstp->rq_addrlen = sizeof(rqstp->rq_addr);
+	sock = rqstp->rq_sock->sk_sock;
+
+	msg.msg_name    = &rqstp->rq_addr;
+	msg.msg_namelen = sizeof(rqstp->rq_addr);
+	msg.msg_control = NULL;
+	msg.msg_controllen = 0;
+
+	msg.msg_flags	= MSG_DONTWAIT;
+
+	len = kernel_recvmsg(sock, &msg, iov, nr, buflen, MSG_DONTWAIT);
+
+	/* sock_recvmsg doesn't fill in the name/namelen, so we must..
+	 * possibly we should cache this in the svc_sock structure
+	 * at accept time. FIXME
+	 */
+	alen = sizeof(rqstp->rq_addr);
+	sock->ops->getname(sock, (struct sockaddr *)&rqstp->rq_addr, &alen, 1);
+
+	dprintk("svc: socket %p recvfrom(%p, %Zu) = %d\n",
+		rqstp->rq_sock, iov[0].iov_base, iov[0].iov_len, len);
+
+	return len;
+}
+
+/*
+ * Set socket snd and rcv buffer lengths
+ */
+static inline void
+svc_sock_setbufsize(struct socket *sock, unsigned int snd, unsigned int rcv)
+{
+#if 0
+	mm_segment_t	oldfs;
+	oldfs = get_fs(); set_fs(KERNEL_DS);
+	sock_setsockopt(sock, SOL_SOCKET, SO_SNDBUF,
+			(char*)&snd, sizeof(snd));
+	sock_setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
+			(char*)&rcv, sizeof(rcv));
+#else
+	/* sock_setsockopt limits use to sysctl_?mem_max,
+	 * which isn't acceptable.  Until that is made conditional
+	 * on not having CAP_SYS_RESOURCE or similar, we go direct...
+	 * DaveM said I could!
+	 */
+	lock_sock(sock->sk);
+	sock->sk->sk_sndbuf = snd * 2;
+	sock->sk->sk_rcvbuf = rcv * 2;
+	sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK|SOCK_RCVBUF_LOCK;
+	release_sock(sock->sk);
+#endif
+}
+/*
+ * INET callback when data has been received on the socket.
+ */
+static void
+svc_udp_data_ready(struct sock *sk, int count)
+{
+	struct svc_sock	*svsk = (struct svc_sock *)(sk->sk_user_data);
+
+	if (!svsk)
+		goto out;
+	dprintk("svc: socket %p(inet %p), count=%d, busy=%d\n",
+		svsk, sk, count, test_bit(SK_BUSY, &svsk->sk_flags));
+	set_bit(SK_DATA, &svsk->sk_flags);
+	svc_sock_enqueue(svsk);
+ out:
+	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
+		wake_up_interruptible(sk->sk_sleep);
+}
+
+/*
+ * INET callback when space is newly available on the socket.
+ */
+static void
+svc_write_space(struct sock *sk)
+{
+	struct svc_sock	*svsk = (struct svc_sock *)(sk->sk_user_data);
+
+	if (svsk) {
+		dprintk("svc: socket %p(inet %p), write_space busy=%d\n",
+			svsk, sk, test_bit(SK_BUSY, &svsk->sk_flags));
+		svc_sock_enqueue(svsk);
+	}
+
+	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) {
+		printk(KERN_WARNING "RPC svc_write_space: some sleeping on %p\n",
+		       svsk);
+		wake_up_interruptible(sk->sk_sleep);
+	}
+}
+
+/*
+ * Receive a datagram from a UDP socket.
+ */
+extern int
+csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb);
+
+static int
+svc_udp_recvfrom(struct svc_rqst *rqstp)
+{
+	struct svc_sock	*svsk = rqstp->rq_sock;
+	struct svc_serv	*serv = svsk->sk_server;
+	struct sk_buff	*skb;
+	int		err, len;
+
+	if (test_and_clear_bit(SK_CHNGBUF, &svsk->sk_flags))
+	    /* udp sockets need large rcvbuf as all pending
+	     * requests are still in that buffer.  sndbuf must
+	     * also be large enough that there is enough space
+	     * for one reply per thread.
+	     */
+	    svc_sock_setbufsize(svsk->sk_sock,
+				(serv->sv_nrthreads+3) * serv->sv_bufsz,
+				(serv->sv_nrthreads+3) * serv->sv_bufsz);
+
+	if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) {
+		svc_sock_received(svsk);
+		return svc_deferred_recv(rqstp);
+	}
+
+	clear_bit(SK_DATA, &svsk->sk_flags);
+	while ((skb = skb_recv_datagram(svsk->sk_sk, 0, 1, &err)) == NULL) {
+		if (err == -EAGAIN) {
+			svc_sock_received(svsk);
+			return err;
+		}
+		/* possibly an icmp error */
+		dprintk("svc: recvfrom returned error %d\n", -err);
+	}
+	if (skb->stamp.tv_sec == 0) {
+		skb->stamp.tv_sec = xtime.tv_sec; 
+		skb->stamp.tv_usec = xtime.tv_nsec * 1000; 
+		/* Don't enable netstamp, sunrpc doesn't 
+		   need that much accuracy */
+	}
+	svsk->sk_sk->sk_stamp = skb->stamp;
+	set_bit(SK_DATA, &svsk->sk_flags); /* there may be more data... */
+
+	/*
+	 * Maybe more packets - kick another thread ASAP.
+	 */
+	svc_sock_received(svsk);
+
+	len  = skb->len - sizeof(struct udphdr);
+	rqstp->rq_arg.len = len;
+
+	rqstp->rq_prot        = IPPROTO_UDP;
+
+	/* Get sender address */
+	rqstp->rq_addr.sin_family = AF_INET;
+	rqstp->rq_addr.sin_port = skb->h.uh->source;
+	rqstp->rq_addr.sin_addr.s_addr = skb->nh.iph->saddr;
+	rqstp->rq_daddr = skb->nh.iph->daddr;
+
+	if (skb_is_nonlinear(skb)) {
+		/* we have to copy */
+		local_bh_disable();
+		if (csum_partial_copy_to_xdr(&rqstp->rq_arg, skb)) {
+			local_bh_enable();
+			/* checksum error */
+			skb_free_datagram(svsk->sk_sk, skb);
+			return 0;
+		}
+		local_bh_enable();
+		skb_free_datagram(svsk->sk_sk, skb); 
+	} else {
+		/* we can use it in-place */
+		rqstp->rq_arg.head[0].iov_base = skb->data + sizeof(struct udphdr);
+		rqstp->rq_arg.head[0].iov_len = len;
+		if (skb->ip_summed != CHECKSUM_UNNECESSARY) {
+			if ((unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum))) {
+				skb_free_datagram(svsk->sk_sk, skb);
+				return 0;
+			}
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+		}
+		rqstp->rq_skbuff = skb;
+	}
+
+	rqstp->rq_arg.page_base = 0;
+	if (len <= rqstp->rq_arg.head[0].iov_len) {
+		rqstp->rq_arg.head[0].iov_len = len;
+		rqstp->rq_arg.page_len = 0;
+	} else {
+		rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
+		rqstp->rq_argused += (rqstp->rq_arg.page_len + PAGE_SIZE - 1)/ PAGE_SIZE;
+	}
+
+	if (serv->sv_stats)
+		serv->sv_stats->netudpcnt++;
+
+	return len;
+}
+
+static int
+svc_udp_sendto(struct svc_rqst *rqstp)
+{
+	int		error;
+
+	error = svc_sendto(rqstp, &rqstp->rq_res);
+	if (error == -ECONNREFUSED)
+		/* ICMP error on earlier request. */
+		error = svc_sendto(rqstp, &rqstp->rq_res);
+
+	return error;
+}
+
+static void
+svc_udp_init(struct svc_sock *svsk)
+{
+	svsk->sk_sk->sk_data_ready = svc_udp_data_ready;
+	svsk->sk_sk->sk_write_space = svc_write_space;
+	svsk->sk_recvfrom = svc_udp_recvfrom;
+	svsk->sk_sendto = svc_udp_sendto;
+
+	/* initialise setting must have enough space to
+	 * receive and respond to one request.  
+	 * svc_udp_recvfrom will re-adjust if necessary
+	 */
+	svc_sock_setbufsize(svsk->sk_sock,
+			    3 * svsk->sk_server->sv_bufsz,
+			    3 * svsk->sk_server->sv_bufsz);
+
+	set_bit(SK_DATA, &svsk->sk_flags); /* might have come in before data_ready set up */
+	set_bit(SK_CHNGBUF, &svsk->sk_flags);
+}
+
+/*
+ * A data_ready event on a listening socket means there's a connection
+ * pending. Do not use state_change as a substitute for it.
+ */
+static void
+svc_tcp_listen_data_ready(struct sock *sk, int count_unused)
+{
+	struct svc_sock	*svsk;
+
+	dprintk("svc: socket %p TCP (listen) state change %d\n",
+			sk, sk->sk_state);
+
+	if  (sk->sk_state != TCP_LISTEN) {
+		/*
+		 * This callback may called twice when a new connection
+		 * is established as a child socket inherits everything
+		 * from a parent LISTEN socket.
+		 * 1) data_ready method of the parent socket will be called
+		 *    when one of child sockets become ESTABLISHED.
+		 * 2) data_ready method of the child socket may be called
+		 *    when it receives data before the socket is accepted.
+		 * In case of 2, we should ignore it silently.
+		 */
+		goto out;
+	}
+	if (!(svsk = (struct svc_sock *) sk->sk_user_data)) {
+		printk("svc: socket %p: no user data\n", sk);
+		goto out;
+	}
+	set_bit(SK_CONN, &svsk->sk_flags);
+	svc_sock_enqueue(svsk);
+ out:
+	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
+		wake_up_interruptible_all(sk->sk_sleep);
+}
+
+/*
+ * A state change on a connected socket means it's dying or dead.
+ */
+static void
+svc_tcp_state_change(struct sock *sk)
+{
+	struct svc_sock	*svsk;
+
+	dprintk("svc: socket %p TCP (connected) state change %d (svsk %p)\n",
+			sk, sk->sk_state, sk->sk_user_data);
+
+	if (!(svsk = (struct svc_sock *) sk->sk_user_data)) {
+		printk("svc: socket %p: no user data\n", sk);
+		goto out;
+	}
+	set_bit(SK_CLOSE, &svsk->sk_flags);
+	svc_sock_enqueue(svsk);
+ out:
+	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
+		wake_up_interruptible_all(sk->sk_sleep);
+}
+
+static void
+svc_tcp_data_ready(struct sock *sk, int count)
+{
+	struct svc_sock *	svsk;
+
+	dprintk("svc: socket %p TCP data ready (svsk %p)\n",
+			sk, sk->sk_user_data);
+	if (!(svsk = (struct svc_sock *)(sk->sk_user_data)))
+		goto out;
+	set_bit(SK_DATA, &svsk->sk_flags);
+	svc_sock_enqueue(svsk);
+ out:
+	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
+		wake_up_interruptible(sk->sk_sleep);
+}
+
+/*
+ * Accept a TCP connection
+ */
+static void
+svc_tcp_accept(struct svc_sock *svsk)
+{
+	struct sockaddr_in sin;
+	struct svc_serv	*serv = svsk->sk_server;
+	struct socket	*sock = svsk->sk_sock;
+	struct socket	*newsock;
+	struct proto_ops *ops;
+	struct svc_sock	*newsvsk;
+	int		err, slen;
+
+	dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
+	if (!sock)
+		return;
+
+	err = sock_create_lite(PF_INET, SOCK_STREAM, IPPROTO_TCP, &newsock);
+	if (err) {
+		if (err == -ENOMEM)
+			printk(KERN_WARNING "%s: no more sockets!\n",
+			       serv->sv_name);
+		return;
+	}
+
+	dprintk("svc: tcp_accept %p allocated\n", newsock);
+	newsock->ops = ops = sock->ops;
+
+	clear_bit(SK_CONN, &svsk->sk_flags);
+	if ((err = ops->accept(sock, newsock, O_NONBLOCK)) < 0) {
+		if (err != -EAGAIN && net_ratelimit())
+			printk(KERN_WARNING "%s: accept failed (err %d)!\n",
+				   serv->sv_name, -err);
+		goto failed;		/* aborted connection or whatever */
+	}
+	set_bit(SK_CONN, &svsk->sk_flags);
+	svc_sock_enqueue(svsk);
+
+	slen = sizeof(sin);
+	err = ops->getname(newsock, (struct sockaddr *) &sin, &slen, 1);
+	if (err < 0) {
+		if (net_ratelimit())
+			printk(KERN_WARNING "%s: peername failed (err %d)!\n",
+				   serv->sv_name, -err);
+		goto failed;		/* aborted connection or whatever */
+	}
+
+	/* Ideally, we would want to reject connections from unauthorized
+	 * hosts here, but when we get encription, the IP of the host won't
+	 * tell us anything. For now just warn about unpriv connections.
+	 */
+	if (ntohs(sin.sin_port) >= 1024) {
+		dprintk(KERN_WARNING
+			"%s: connect from unprivileged port: %u.%u.%u.%u:%d\n",
+			serv->sv_name, 
+			NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port));
+	}
+
+	dprintk("%s: connect from %u.%u.%u.%u:%04x\n", serv->sv_name,
+			NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port));
+
+	/* make sure that a write doesn't block forever when
+	 * low on memory
+	 */
+	newsock->sk->sk_sndtimeo = HZ*30;
+
+	if (!(newsvsk = svc_setup_socket(serv, newsock, &err, 0)))
+		goto failed;
+
+
+	/* make sure that we don't have too many active connections.
+	 * If we have, something must be dropped.
+	 *
+	 * There's no point in trying to do random drop here for
+	 * DoS prevention. The NFS clients does 1 reconnect in 15
+	 * seconds. An attacker can easily beat that.
+	 *
+	 * The only somewhat efficient mechanism would be if drop
+	 * old connections from the same IP first. But right now
+	 * we don't even record the client IP in svc_sock.
+	 */
+	if (serv->sv_tmpcnt > (serv->sv_nrthreads+3)*20) {
+		struct svc_sock *svsk = NULL;
+		spin_lock_bh(&serv->sv_lock);
+		if (!list_empty(&serv->sv_tempsocks)) {
+			if (net_ratelimit()) {
+				/* Try to help the admin */
+				printk(KERN_NOTICE "%s: too many open TCP "
+					"sockets, consider increasing the "
+					"number of nfsd threads\n",
+						   serv->sv_name);
+				printk(KERN_NOTICE "%s: last TCP connect from "
+					"%u.%u.%u.%u:%d\n",
+					serv->sv_name,
+					NIPQUAD(sin.sin_addr.s_addr),
+					ntohs(sin.sin_port));
+			}
+			/*
+			 * Always select the oldest socket. It's not fair,
+			 * but so is life
+			 */
+			svsk = list_entry(serv->sv_tempsocks.prev,
+					  struct svc_sock,
+					  sk_list);
+			set_bit(SK_CLOSE, &svsk->sk_flags);
+			svsk->sk_inuse ++;
+		}
+		spin_unlock_bh(&serv->sv_lock);
+
+		if (svsk) {
+			svc_sock_enqueue(svsk);
+			svc_sock_put(svsk);
+		}
+
+	}
+
+	if (serv->sv_stats)
+		serv->sv_stats->nettcpconn++;
+
+	return;
+
+failed:
+	sock_release(newsock);
+	return;
+}
+
+/*
+ * Receive data from a TCP socket.
+ */
+static int
+svc_tcp_recvfrom(struct svc_rqst *rqstp)
+{
+	struct svc_sock	*svsk = rqstp->rq_sock;
+	struct svc_serv	*serv = svsk->sk_server;
+	int		len;
+	struct kvec vec[RPCSVC_MAXPAGES];
+	int pnum, vlen;
+
+	dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
+		svsk, test_bit(SK_DATA, &svsk->sk_flags),
+		test_bit(SK_CONN, &svsk->sk_flags),
+		test_bit(SK_CLOSE, &svsk->sk_flags));
+
+	if ((rqstp->rq_deferred = svc_deferred_dequeue(svsk))) {
+		svc_sock_received(svsk);
+		return svc_deferred_recv(rqstp);
+	}
+
+	if (test_bit(SK_CLOSE, &svsk->sk_flags)) {
+		svc_delete_socket(svsk);
+		return 0;
+	}
+
+	if (test_bit(SK_CONN, &svsk->sk_flags)) {
+		svc_tcp_accept(svsk);
+		svc_sock_received(svsk);
+		return 0;
+	}
+
+	if (test_and_clear_bit(SK_CHNGBUF, &svsk->sk_flags))
+		/* sndbuf needs to have room for one request
+		 * per thread, otherwise we can stall even when the
+		 * network isn't a bottleneck.
+		 * rcvbuf just needs to be able to hold a few requests.
+		 * Normally they will be removed from the queue 
+		 * as soon a a complete request arrives.
+		 */
+		svc_sock_setbufsize(svsk->sk_sock,
+				    (serv->sv_nrthreads+3) * serv->sv_bufsz,
+				    3 * serv->sv_bufsz);
+
+	clear_bit(SK_DATA, &svsk->sk_flags);
+
+	/* Receive data. If we haven't got the record length yet, get
+	 * the next four bytes. Otherwise try to gobble up as much as
+	 * possible up to the complete record length.
+	 */
+	if (svsk->sk_tcplen < 4) {
+		unsigned long	want = 4 - svsk->sk_tcplen;
+		struct kvec	iov;
+
+		iov.iov_base = ((char *) &svsk->sk_reclen) + svsk->sk_tcplen;
+		iov.iov_len  = want;
+		if ((len = svc_recvfrom(rqstp, &iov, 1, want)) < 0)
+			goto error;
+		svsk->sk_tcplen += len;
+
+		if (len < want) {
+			dprintk("svc: short recvfrom while reading record length (%d of %lu)\n",
+			        len, want);
+			svc_sock_received(svsk);
+			return -EAGAIN; /* record header not complete */
+		}
+
+		svsk->sk_reclen = ntohl(svsk->sk_reclen);
+		if (!(svsk->sk_reclen & 0x80000000)) {
+			/* FIXME: technically, a record can be fragmented,
+			 *  and non-terminal fragments will not have the top
+			 *  bit set in the fragment length header.
+			 *  But apparently no known nfs clients send fragmented
+			 *  records. */
+			printk(KERN_NOTICE "RPC: bad TCP reclen 0x%08lx (non-terminal)\n",
+			       (unsigned long) svsk->sk_reclen);
+			goto err_delete;
+		}
+		svsk->sk_reclen &= 0x7fffffff;
+		dprintk("svc: TCP record, %d bytes\n", svsk->sk_reclen);
+		if (svsk->sk_reclen > serv->sv_bufsz) {
+			printk(KERN_NOTICE "RPC: bad TCP reclen 0x%08lx (large)\n",
+			       (unsigned long) svsk->sk_reclen);
+			goto err_delete;
+		}
+	}
+
+	/* Check whether enough data is available */
+	len = svc_recv_available(svsk);
+	if (len < 0)
+		goto error;
+
+	if (len < svsk->sk_reclen) {
+		dprintk("svc: incomplete TCP record (%d of %d)\n",
+			len, svsk->sk_reclen);
+		svc_sock_received(svsk);
+		return -EAGAIN;	/* record not complete */
+	}
+	len = svsk->sk_reclen;
+	set_bit(SK_DATA, &svsk->sk_flags);
+
+	vec[0] = rqstp->rq_arg.head[0];
+	vlen = PAGE_SIZE;
+	pnum = 1;
+	while (vlen < len) {
+		vec[pnum].iov_base = page_address(rqstp->rq_argpages[rqstp->rq_argused++]);
+		vec[pnum].iov_len = PAGE_SIZE;
+		pnum++;
+		vlen += PAGE_SIZE;
+	}
+
+	/* Now receive data */
+	len = svc_recvfrom(rqstp, vec, pnum, len);
+	if (len < 0)
+		goto error;
+
+	dprintk("svc: TCP complete record (%d bytes)\n", len);
+	rqstp->rq_arg.len = len;
+	rqstp->rq_arg.page_base = 0;
+	if (len <= rqstp->rq_arg.head[0].iov_len) {
+		rqstp->rq_arg.head[0].iov_len = len;
+		rqstp->rq_arg.page_len = 0;
+	} else {
+		rqstp->rq_arg.page_len = len - rqstp->rq_arg.head[0].iov_len;
+	}
+
+	rqstp->rq_skbuff      = NULL;
+	rqstp->rq_prot	      = IPPROTO_TCP;
+
+	/* Reset TCP read info */
+	svsk->sk_reclen = 0;
+	svsk->sk_tcplen = 0;
+
+	svc_sock_received(svsk);
+	if (serv->sv_stats)
+		serv->sv_stats->nettcpcnt++;
+
+	return len;
+
+ err_delete:
+	svc_delete_socket(svsk);
+	return -EAGAIN;
+
+ error:
+	if (len == -EAGAIN) {
+		dprintk("RPC: TCP recvfrom got EAGAIN\n");
+		svc_sock_received(svsk);
+	} else {
+		printk(KERN_NOTICE "%s: recvfrom returned errno %d\n",
+					svsk->sk_server->sv_name, -len);
+		svc_sock_received(svsk);
+	}
+
+	return len;
+}
+
+/*
+ * Send out data on TCP socket.
+ */
+static int
+svc_tcp_sendto(struct svc_rqst *rqstp)
+{
+	struct xdr_buf	*xbufp = &rqstp->rq_res;
+	int sent;
+	u32 reclen;
+
+	/* Set up the first element of the reply kvec.
+	 * Any other kvecs that may be in use have been taken
+	 * care of by the server implementation itself.
+	 */
+	reclen = htonl(0x80000000|((xbufp->len ) - 4));
+	memcpy(xbufp->head[0].iov_base, &reclen, 4);
+
+	if (test_bit(SK_DEAD, &rqstp->rq_sock->sk_flags))
+		return -ENOTCONN;
+
+	sent = svc_sendto(rqstp, &rqstp->rq_res);
+	if (sent != xbufp->len) {
+		printk(KERN_NOTICE "rpc-srv/tcp: %s: %s %d when sending %d bytes - shutting down socket\n",
+		       rqstp->rq_sock->sk_server->sv_name,
+		       (sent<0)?"got error":"sent only",
+		       sent, xbufp->len);
+		svc_delete_socket(rqstp->rq_sock);
+		sent = -EAGAIN;
+	}
+	return sent;
+}
+
+static void
+svc_tcp_init(struct svc_sock *svsk)
+{
+	struct sock	*sk = svsk->sk_sk;
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	svsk->sk_recvfrom = svc_tcp_recvfrom;
+	svsk->sk_sendto = svc_tcp_sendto;
+
+	if (sk->sk_state == TCP_LISTEN) {
+		dprintk("setting up TCP socket for listening\n");
+		sk->sk_data_ready = svc_tcp_listen_data_ready;
+		set_bit(SK_CONN, &svsk->sk_flags);
+	} else {
+		dprintk("setting up TCP socket for reading\n");
+		sk->sk_state_change = svc_tcp_state_change;
+		sk->sk_data_ready = svc_tcp_data_ready;
+		sk->sk_write_space = svc_write_space;
+
+		svsk->sk_reclen = 0;
+		svsk->sk_tcplen = 0;
+
+		tp->nonagle = 1;        /* disable Nagle's algorithm */
+
+		/* initialise setting must have enough space to
+		 * receive and respond to one request.  
+		 * svc_tcp_recvfrom will re-adjust if necessary
+		 */
+		svc_sock_setbufsize(svsk->sk_sock,
+				    3 * svsk->sk_server->sv_bufsz,
+				    3 * svsk->sk_server->sv_bufsz);
+
+		set_bit(SK_CHNGBUF, &svsk->sk_flags);
+		set_bit(SK_DATA, &svsk->sk_flags);
+		if (sk->sk_state != TCP_ESTABLISHED) 
+			set_bit(SK_CLOSE, &svsk->sk_flags);
+	}
+}
+
+void
+svc_sock_update_bufs(struct svc_serv *serv)
+{
+	/*
+	 * The number of server threads has changed. Update
+	 * rcvbuf and sndbuf accordingly on all sockets
+	 */
+	struct list_head *le;
+
+	spin_lock_bh(&serv->sv_lock);
+	list_for_each(le, &serv->sv_permsocks) {
+		struct svc_sock *svsk = 
+			list_entry(le, struct svc_sock, sk_list);
+		set_bit(SK_CHNGBUF, &svsk->sk_flags);
+	}
+	list_for_each(le, &serv->sv_tempsocks) {
+		struct svc_sock *svsk =
+			list_entry(le, struct svc_sock, sk_list);
+		set_bit(SK_CHNGBUF, &svsk->sk_flags);
+	}
+	spin_unlock_bh(&serv->sv_lock);
+}
+
+/*
+ * Receive the next request on any socket.
+ */
+int
+svc_recv(struct svc_serv *serv, struct svc_rqst *rqstp, long timeout)
+{
+	struct svc_sock		*svsk =NULL;
+	int			len;
+	int 			pages;
+	struct xdr_buf		*arg;
+	DECLARE_WAITQUEUE(wait, current);
+
+	dprintk("svc: server %p waiting for data (to = %ld)\n",
+		rqstp, timeout);
+
+	if (rqstp->rq_sock)
+		printk(KERN_ERR 
+			"svc_recv: service %p, socket not NULL!\n",
+			 rqstp);
+	if (waitqueue_active(&rqstp->rq_wait))
+		printk(KERN_ERR 
+			"svc_recv: service %p, wait queue active!\n",
+			 rqstp);
+
+	/* Initialize the buffers */
+	/* first reclaim pages that were moved to response list */
+	svc_pushback_allpages(rqstp);
+
+	/* now allocate needed pages.  If we get a failure, sleep briefly */
+	pages = 2 + (serv->sv_bufsz + PAGE_SIZE -1) / PAGE_SIZE;
+	while (rqstp->rq_arghi < pages) {
+		struct page *p = alloc_page(GFP_KERNEL);
+		if (!p) {
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			schedule_timeout(HZ/2);
+			continue;
+		}
+		rqstp->rq_argpages[rqstp->rq_arghi++] = p;
+	}
+
+	/* Make arg->head point to first page and arg->pages point to rest */
+	arg = &rqstp->rq_arg;
+	arg->head[0].iov_base = page_address(rqstp->rq_argpages[0]);
+	arg->head[0].iov_len = PAGE_SIZE;
+	rqstp->rq_argused = 1;
+	arg->pages = rqstp->rq_argpages + 1;
+	arg->page_base = 0;
+	/* save at least one page for response */
+	arg->page_len = (pages-2)*PAGE_SIZE;
+	arg->len = (pages-1)*PAGE_SIZE;
+	arg->tail[0].iov_len = 0;
+	
+	try_to_freeze(PF_FREEZE);
+	if (signalled())
+		return -EINTR;
+
+	spin_lock_bh(&serv->sv_lock);
+	if (!list_empty(&serv->sv_tempsocks)) {
+		svsk = list_entry(serv->sv_tempsocks.next,
+				  struct svc_sock, sk_list);
+		/* apparently the "standard" is that clients close
+		 * idle connections after 5 minutes, servers after
+		 * 6 minutes
+		 *   http://www.connectathon.org/talks96/nfstcp.pdf 
+		 */
+		if (get_seconds() - svsk->sk_lastrecv < 6*60
+		    || test_bit(SK_BUSY, &svsk->sk_flags))
+			svsk = NULL;
+	}
+	if (svsk) {
+		set_bit(SK_BUSY, &svsk->sk_flags);
+		set_bit(SK_CLOSE, &svsk->sk_flags);
+		rqstp->rq_sock = svsk;
+		svsk->sk_inuse++;
+	} else if ((svsk = svc_sock_dequeue(serv)) != NULL) {
+		rqstp->rq_sock = svsk;
+		svsk->sk_inuse++;
+		rqstp->rq_reserved = serv->sv_bufsz;	
+		svsk->sk_reserved += rqstp->rq_reserved;
+	} else {
+		/* No data pending. Go to sleep */
+		svc_serv_enqueue(serv, rqstp);
+
+		/*
+		 * We have to be able to interrupt this wait
+		 * to bring down the daemons ...
+		 */
+		set_current_state(TASK_INTERRUPTIBLE);
+		add_wait_queue(&rqstp->rq_wait, &wait);
+		spin_unlock_bh(&serv->sv_lock);
+
+		schedule_timeout(timeout);
+
+		try_to_freeze(PF_FREEZE);
+
+		spin_lock_bh(&serv->sv_lock);
+		remove_wait_queue(&rqstp->rq_wait, &wait);
+
+		if (!(svsk = rqstp->rq_sock)) {
+			svc_serv_dequeue(serv, rqstp);
+			spin_unlock_bh(&serv->sv_lock);
+			dprintk("svc: server %p, no data yet\n", rqstp);
+			return signalled()? -EINTR : -EAGAIN;
+		}
+	}
+	spin_unlock_bh(&serv->sv_lock);
+
+	dprintk("svc: server %p, socket %p, inuse=%d\n",
+		 rqstp, svsk, svsk->sk_inuse);
+	len = svsk->sk_recvfrom(rqstp);
+	dprintk("svc: got len=%d\n", len);
+
+	/* No data, incomplete (TCP) read, or accept() */
+	if (len == 0 || len == -EAGAIN) {
+		rqstp->rq_res.len = 0;
+		svc_sock_release(rqstp);
+		return -EAGAIN;
+	}
+	svsk->sk_lastrecv = get_seconds();
+	if (test_bit(SK_TEMP, &svsk->sk_flags)) {
+		/* push active sockets to end of list */
+		spin_lock_bh(&serv->sv_lock);
+		if (!list_empty(&svsk->sk_list))
+			list_move_tail(&svsk->sk_list, &serv->sv_tempsocks);
+		spin_unlock_bh(&serv->sv_lock);
+	}
+
+	rqstp->rq_secure  = ntohs(rqstp->rq_addr.sin_port) < 1024;
+	rqstp->rq_chandle.defer = svc_defer;
+
+	if (serv->sv_stats)
+		serv->sv_stats->netcnt++;
+	return len;
+}
+
+/* 
+ * Drop request
+ */
+void
+svc_drop(struct svc_rqst *rqstp)
+{
+	dprintk("svc: socket %p dropped request\n", rqstp->rq_sock);
+	svc_sock_release(rqstp);
+}
+
+/*
+ * Return reply to client.
+ */
+int
+svc_send(struct svc_rqst *rqstp)
+{
+	struct svc_sock	*svsk;
+	int		len;
+	struct xdr_buf	*xb;
+
+	if ((svsk = rqstp->rq_sock) == NULL) {
+		printk(KERN_WARNING "NULL socket pointer in %s:%d\n",
+				__FILE__, __LINE__);
+		return -EFAULT;
+	}
+
+	/* release the receive skb before sending the reply */
+	svc_release_skb(rqstp);
+
+	/* calculate over-all length */
+	xb = & rqstp->rq_res;
+	xb->len = xb->head[0].iov_len +
+		xb->page_len +
+		xb->tail[0].iov_len;
+
+	/* Grab svsk->sk_sem to serialize outgoing data. */
+	down(&svsk->sk_sem);
+	if (test_bit(SK_DEAD, &svsk->sk_flags))
+		len = -ENOTCONN;
+	else
+		len = svsk->sk_sendto(rqstp);
+	up(&svsk->sk_sem);
+	svc_sock_release(rqstp);
+
+	if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
+		return 0;
+	return len;
+}
+
+/*
+ * Initialize socket for RPC use and create svc_sock struct
+ * XXX: May want to setsockopt SO_SNDBUF and SO_RCVBUF.
+ */
+static struct svc_sock *
+svc_setup_socket(struct svc_serv *serv, struct socket *sock,
+					int *errp, int pmap_register)
+{
+	struct svc_sock	*svsk;
+	struct sock	*inet;
+
+	dprintk("svc: svc_setup_socket %p\n", sock);
+	if (!(svsk = kmalloc(sizeof(*svsk), GFP_KERNEL))) {
+		*errp = -ENOMEM;
+		return NULL;
+	}
+	memset(svsk, 0, sizeof(*svsk));
+
+	inet = sock->sk;
+
+	/* Register socket with portmapper */
+	if (*errp >= 0 && pmap_register)
+		*errp = svc_register(serv, inet->sk_protocol,
+				     ntohs(inet_sk(inet)->sport));
+
+	if (*errp < 0) {
+		kfree(svsk);
+		return NULL;
+	}
+
+	set_bit(SK_BUSY, &svsk->sk_flags);
+	inet->sk_user_data = svsk;
+	svsk->sk_sock = sock;
+	svsk->sk_sk = inet;
+	svsk->sk_ostate = inet->sk_state_change;
+	svsk->sk_odata = inet->sk_data_ready;
+	svsk->sk_owspace = inet->sk_write_space;
+	svsk->sk_server = serv;
+	svsk->sk_lastrecv = get_seconds();
+	INIT_LIST_HEAD(&svsk->sk_deferred);
+	INIT_LIST_HEAD(&svsk->sk_ready);
+	sema_init(&svsk->sk_sem, 1);
+
+	/* Initialize the socket */
+	if (sock->type == SOCK_DGRAM)
+		svc_udp_init(svsk);
+	else
+		svc_tcp_init(svsk);
+
+	spin_lock_bh(&serv->sv_lock);
+	if (!pmap_register) {
+		set_bit(SK_TEMP, &svsk->sk_flags);
+		list_add(&svsk->sk_list, &serv->sv_tempsocks);
+		serv->sv_tmpcnt++;
+	} else {
+		clear_bit(SK_TEMP, &svsk->sk_flags);
+		list_add(&svsk->sk_list, &serv->sv_permsocks);
+	}
+	spin_unlock_bh(&serv->sv_lock);
+
+	dprintk("svc: svc_setup_socket created %p (inet %p)\n",
+				svsk, svsk->sk_sk);
+
+	clear_bit(SK_BUSY, &svsk->sk_flags);
+	svc_sock_enqueue(svsk);
+	return svsk;
+}
+
+/*
+ * Create socket for RPC service.
+ */
+static int
+svc_create_socket(struct svc_serv *serv, int protocol, struct sockaddr_in *sin)
+{
+	struct svc_sock	*svsk;
+	struct socket	*sock;
+	int		error;
+	int		type;
+
+	dprintk("svc: svc_create_socket(%s, %d, %u.%u.%u.%u:%d)\n",
+				serv->sv_program->pg_name, protocol,
+				NIPQUAD(sin->sin_addr.s_addr),
+				ntohs(sin->sin_port));
+
+	if (protocol != IPPROTO_UDP && protocol != IPPROTO_TCP) {
+		printk(KERN_WARNING "svc: only UDP and TCP "
+				"sockets supported\n");
+		return -EINVAL;
+	}
+	type = (protocol == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
+
+	if ((error = sock_create_kern(PF_INET, type, protocol, &sock)) < 0)
+		return error;
+
+	if (sin != NULL) {
+		if (type == SOCK_STREAM)
+			sock->sk->sk_reuse = 1; /* allow address reuse */
+		error = sock->ops->bind(sock, (struct sockaddr *) sin,
+						sizeof(*sin));
+		if (error < 0)
+			goto bummer;
+	}
+
+	if (protocol == IPPROTO_TCP) {
+		if ((error = sock->ops->listen(sock, 64)) < 0)
+			goto bummer;
+	}
+
+	if ((svsk = svc_setup_socket(serv, sock, &error, 1)) != NULL)
+		return 0;
+
+bummer:
+	dprintk("svc: svc_create_socket error = %d\n", -error);
+	sock_release(sock);
+	return error;
+}
+
+/*
+ * Remove a dead socket
+ */
+void
+svc_delete_socket(struct svc_sock *svsk)
+{
+	struct svc_serv	*serv;
+	struct sock	*sk;
+
+	dprintk("svc: svc_delete_socket(%p)\n", svsk);
+
+	serv = svsk->sk_server;
+	sk = svsk->sk_sk;
+
+	sk->sk_state_change = svsk->sk_ostate;
+	sk->sk_data_ready = svsk->sk_odata;
+	sk->sk_write_space = svsk->sk_owspace;
+
+	spin_lock_bh(&serv->sv_lock);
+
+	list_del_init(&svsk->sk_list);
+	list_del_init(&svsk->sk_ready);
+	if (!test_and_set_bit(SK_DEAD, &svsk->sk_flags))
+		if (test_bit(SK_TEMP, &svsk->sk_flags))
+			serv->sv_tmpcnt--;
+
+	if (!svsk->sk_inuse) {
+		spin_unlock_bh(&serv->sv_lock);
+		sock_release(svsk->sk_sock);
+		kfree(svsk);
+	} else {
+		spin_unlock_bh(&serv->sv_lock);
+		dprintk(KERN_NOTICE "svc: server socket destroy delayed\n");
+		/* svsk->sk_server = NULL; */
+	}
+}
+
+/*
+ * Make a socket for nfsd and lockd
+ */
+int
+svc_makesock(struct svc_serv *serv, int protocol, unsigned short port)
+{
+	struct sockaddr_in	sin;
+
+	dprintk("svc: creating socket proto = %d\n", protocol);
+	sin.sin_family      = AF_INET;
+	sin.sin_addr.s_addr = INADDR_ANY;
+	sin.sin_port        = htons(port);
+	return svc_create_socket(serv, protocol, &sin);
+}
+
+/*
+ * Handle defer and revisit of requests 
+ */
+
+static void svc_revisit(struct cache_deferred_req *dreq, int too_many)
+{
+	struct svc_deferred_req *dr = container_of(dreq, struct svc_deferred_req, handle);
+	struct svc_serv *serv = dreq->owner;
+	struct svc_sock *svsk;
+
+	if (too_many) {
+		svc_sock_put(dr->svsk);
+		kfree(dr);
+		return;
+	}
+	dprintk("revisit queued\n");
+	svsk = dr->svsk;
+	dr->svsk = NULL;
+	spin_lock_bh(&serv->sv_lock);
+	list_add(&dr->handle.recent, &svsk->sk_deferred);
+	spin_unlock_bh(&serv->sv_lock);
+	set_bit(SK_DEFERRED, &svsk->sk_flags);
+	svc_sock_enqueue(svsk);
+	svc_sock_put(svsk);
+}
+
+static struct cache_deferred_req *
+svc_defer(struct cache_req *req)
+{
+	struct svc_rqst *rqstp = container_of(req, struct svc_rqst, rq_chandle);
+	int size = sizeof(struct svc_deferred_req) + (rqstp->rq_arg.len);
+	struct svc_deferred_req *dr;
+
+	if (rqstp->rq_arg.page_len)
+		return NULL; /* if more than a page, give up FIXME */
+	if (rqstp->rq_deferred) {
+		dr = rqstp->rq_deferred;
+		rqstp->rq_deferred = NULL;
+	} else {
+		int skip  = rqstp->rq_arg.len - rqstp->rq_arg.head[0].iov_len;
+		/* FIXME maybe discard if size too large */
+		dr = kmalloc(size, GFP_KERNEL);
+		if (dr == NULL)
+			return NULL;
+
+		dr->handle.owner = rqstp->rq_server;
+		dr->prot = rqstp->rq_prot;
+		dr->addr = rqstp->rq_addr;
+		dr->argslen = rqstp->rq_arg.len >> 2;
+		memcpy(dr->args, rqstp->rq_arg.head[0].iov_base-skip, dr->argslen<<2);
+	}
+	spin_lock_bh(&rqstp->rq_server->sv_lock);
+	rqstp->rq_sock->sk_inuse++;
+	dr->svsk = rqstp->rq_sock;
+	spin_unlock_bh(&rqstp->rq_server->sv_lock);
+
+	dr->handle.revisit = svc_revisit;
+	return &dr->handle;
+}
+
+/*
+ * recv data from a deferred request into an active one
+ */
+static int svc_deferred_recv(struct svc_rqst *rqstp)
+{
+	struct svc_deferred_req *dr = rqstp->rq_deferred;
+
+	rqstp->rq_arg.head[0].iov_base = dr->args;
+	rqstp->rq_arg.head[0].iov_len = dr->argslen<<2;
+	rqstp->rq_arg.page_len = 0;
+	rqstp->rq_arg.len = dr->argslen<<2;
+	rqstp->rq_prot        = dr->prot;
+	rqstp->rq_addr        = dr->addr;
+	return dr->argslen<<2;
+}
+
+
+static struct svc_deferred_req *svc_deferred_dequeue(struct svc_sock *svsk)
+{
+	struct svc_deferred_req *dr = NULL;
+	struct svc_serv	*serv = svsk->sk_server;
+	
+	if (!test_bit(SK_DEFERRED, &svsk->sk_flags))
+		return NULL;
+	spin_lock_bh(&serv->sv_lock);
+	clear_bit(SK_DEFERRED, &svsk->sk_flags);
+	if (!list_empty(&svsk->sk_deferred)) {
+		dr = list_entry(svsk->sk_deferred.next,
+				struct svc_deferred_req,
+				handle.recent);
+		list_del_init(&dr->handle.recent);
+		set_bit(SK_DEFERRED, &svsk->sk_flags);
+	}
+	spin_unlock_bh(&serv->sv_lock);
+	return dr;
+}